Officials want to test whether drivers are obeying the posted speed limit of 65 mph.
Sample: 55 vehicles.
Average speed of sample: 69 miles
Standard deviation: 7 miles
95% confidence level desired.
Test the hypothesis that mean speed is less than or equal to 65 mph against its one-sided alternative.
Please see the attachment.
Null hypothesis H0: mu<=65
Alternative hypothesis Ha: mu>65.
Use z-test. The sample mean ...
This solution consists of a detailed explanation of testing a hypothesis using the so-called five-step procedure.